E. officinalis (Amla) fruit is one of the key constituents of the celebrated Ayurvedic preparation, Chyavanaprash, used in India for thousands of years as a vitalizing and rejuvenating health tonic. The low molecular weight hydrolyzable, gallo- and ellagi tannins (Ghosal, S. et al., Indian J. Chem., 1996, 35B, 941-48) of the fruit provide multi-pronged benefits arising out of their antioxidative, hypocholesterolemic, immunomodulating and HMG CoA reductase inhibitive properties. While its LDL-cholesterol lowering property has been described in published literature, the more desirable property of enhancing HDL cholesterol, as described in the present invention, was not noted before. Similarly, no earlier work had studied the antiinflammatory properties of amla, as observed in the present invention. Reduction of fasting glucose levels consequent to amla consumption is another desirable property observed in the present invention. We have also now surprisingly found that E. officinalis fruit extract reduces intima-media thickening in experimental animals. This observation, though limited to experimental animals, is also reported for the first time. The cumulative effect of the reduction of multiple risk factors by amla extract is the potential regression of this major disease. Thus the beneficial effects of the present inventive composition goes beyond the simple correction of LDL cholesterol levels, as achieved in previous studies.
Coronary heart disease (CHD) continues to be the major cause of premature death in most developed and developing countries. A low level of HDL cholesterol is the second most important risk factor for CHD, as demonstrated in numerous clinical and epidemiological studies (Gorden, D. and Rifkind, H. M., N. Engl. J. Med., 1989, 321:1311-1315; Brewer, Jr., H. B., New Engl. J. Med, 2004, 350:1491-94) and HDL has emerged, during the past decade, as a new potential target for the treatment of cardiovascular diseases. The key role of HDL as a carrier of excess cellular cholesterol in the reverse cholesterol transport pathway is believed to provide protection against atherosclerosis. In reverse cholesterol transport, peripheral tissues, for example, vessel-wall macrophages, remove their excess cholesterol through the ATP-binding cassette transporter 1 (ABCA1) to poorly lipidated apolipoprotein A-I, forming pre-β-HDL. Lecithin-cholesterol acyltransferase then esterifies free cholesterol to cholesteryl esters, converting pre-β-HDL to mature spherical α-HDL.
HDL cholesterol is transported to the liver by two pathways: 1) it is delivered directly to the liver through interaction with the scavenger receptor, class B, type I (SR-BI); 2) cholesteryl esters in HDL are transferred by the cholesterol ester transferase protein (CETP) to very-low-density-lipoproteins (VLDL) and low-density lipoproteins (LDL) and are then returned to the liver through the LDL receptor. HDL cholesterol that is taken up by the liver is then excreted in the form of bile acids and cholesterol, completing the process of reverse cholesterol transport (Brewer, H. B. Jr., Arterioscl. Thromb. Vasc. Biol., 2004, 24:387-91). HDL is believed to have the ability to remove cholesterol from macrophages, thus preventing the formation of foam cells.
A second beneficial role of HDL in atherosclerosis is in protecting LDL from oxidation (Navab, M. et al, Circulation, 2002, 105:290-92). Unlike normal LDL, oxidized LDL is readily taken up by macrophage scavenger receptor SR-A or CD36 resulting in the formation of foam cells. Foam cells are a major component of the early atherosclerotic lesion. Further, HDL may slow the progression of lesions by selectively decreasing the production of endothelial cell-adhesion molecules that facilitate the uptake of cells into the vessel wall (Barter, P. J., et al, Curr. Opin. Lipid, 2002, 13:285-88). HDL may also prolong the half-life of prostacycline and preserve its vasodilatory effect (Mackness, M. I. et al, Atherosclerosis, 1993, 104:129-35).
Several lines of evidence support the concept that increasing the HDL level may provide protection against the development of atherosclerosis. Epidemiologic studies have shown an inverse relation between HDL cholesterol levels and the risk of cardiovascular disease. Increasing the HDL cholesterol level by 1 mg may reduce the risk of cardiovascular disease by 2 to 3 per cent. Overexpressing the apo-A-I gene in transgenic mice and rabbits and infusing complexes consisting of apo A-I and phospholipids into hyperlipidemic rabbits increase HDL cholesterol levels and decrease the development of atherosclerosis (Brewer, H B, Jr., loc. cit). In humans, infusing either of these complexes or pro-apo-A-I results in short term increase in HDL cholesterol, biliary cholesterol and fecal cholesterol loss, reinforcing the concept that elevating the HDL cholesterol level decreases the risk of cardiovascular disease.
More than 40 per cent of patients with myocardial infarction have low HDL-C as a cardiac risk factor. (Genest, J. J., et al, Am. J. Cardiol., 1991, 67:1185-89). In the prospective and multicentric European Concerted Action on Thrombosis and Disabilities (ECAT) Angina Pectoris Study, Bolibar et al (Thromb. Haemost., 2000, 84:955-61) identified low HDL-C and low apoA-I as the most important biochemical risk factors for coronary events in patients with angiographically assessed CHD. By convention, the risk threshold value of HDL-C has been defined as 35 mg/dL(0.9 mmol/L) in men and 45 mg/dL (1.15 mmol/L) in women [Expert panel on detection, evaluation and treatment of high blood cholesterol in adults. The second report of the National Cholesterol Education Program (NCEP) expert panel on detection, evaluation and treatment of high blood cholesterol in adults (Adult Treatment Panel II). Circulation. 1994; 89:1329-1445)]. Because of interaction, the strength of the association between HDL-C and cardiovascular risk depends on the presence of additional risk factors. Therefore, threshold values are higher in men with diabetes mellitus or hypercholesterolemia or in the presence of multiple risk factors (von Eckardstein A, and Assmann G. Curr Opin Lipidol. 2000; 11:627-637). Low HDL-C has been identified as the most frequent familial dyslipoproteinemia in patients with premature myocardial infarction (Genest, J. J. Jr., Circulation. 1992; 85:2025-2033). Finally, in the Helsinki Heart Study (Manninen, V. et al, Circulation. 1992; 85:37-45) and the High-Density-Lipoprotein Cholesterol Intervention Trial of the Department of Veterans Affairs (VA-HIT) study (Rubins, H. B. et al, N Engl J Med. 1999; 341:410-418), increases of HDL-C on treatment with gemfibrozil were correlated with the prevention of CHD events. Thus, HDL-C has become an important component of algorithms to assess the global cardiovascular risk of patients and also a target for therapeutic intervention and for the definition of treatment goals.
Strategies to correct dyslipidemia in atherosclerosis generally involve diet and/or drugs. The threshold serum total cholesterol and LDL cholesterol concentrations above which diet and drug therapy should be initiated, as well as the goals of therapy, have been defined by the National Cholesterol Education Program (JAMA, 1993, 269:3015-23). The target serum LDL-C is <160 mg/dl (4.3 mmol/l) for patients with no risk factors or only one risk factor for CHD; <130 mg/dl (3.4 mmol/l) for patients with 2 or more risk factors and less than 100 mg/dl (2.6 mmol/l) for those with CHD. Persons with diabetes also fall into the third category. A reasonable target for triglyceride concentration is 200 mg/dl or less; higher values are associated with a doubling of the risk of cardiovascular disease when serum cholesterol concentration exceeds 240 mg/dl or when the LDL-C/HDL-C ratio exceeds 5:1.
A number of studies have shown that reducing serum LDL-C below the target levels does not necessarily result in proportional reduction in the risk of CHD [(The Scandinavian Simvastatin Survival Study Group. Randomized trial of cholesterol lowering in 4444 patients with coronary heart disease, Lancet, 1994, 344:1383-89; Shepherd, J. et al, N. Engl. J. Med., 1995, 333:1301-7; Sachs, F. M. et al, N. Engl. J. Med., 1998, 315:1001-9; Circulation, 1998, 97:1446-52; The West of Scotland Coronary Prevention Study Group, Circulation, 1998, 97:1440-45; Pederson, T. R., Circulation, 1998, 97:1453-60] because of the attenuation of the cholesterol-heart disease relation at lower serum cholesterol concentrations (Grundy, S. M., Circulation, 1998, 97:1436-39).
Dietary treatment of hyperlipidemia is a necessary foundation for drug treatment. Depending on the degree of hyperlipidemia, the Step I and Step II diets can be introduced sequentially. The Step II diet contains no more than 30% of calories from fat, less than 7% of calories from saturated fatty acids and less than 200 mg of cholesterol per day. In long term studies, the Step II diet decreased serum LDL-C concentrations 8-15% (Knopp, R. H., et al, JAMA, 1997, 278:1509-15; Walden, C. E., Arterioscl. Thromb. Vasc. Biol., 1997, 17:375-82; Denke, M. A., Arch. Intern. Med., 1995, 156:17-26). Diets more restricted in fat than the Step II diet result in little additional reduction in LDL-C, raise serum TG concentration and lower HDL-C.
The point to note, from the above, is that reducing LDL-C alone is of little value in reducing the risk of CHD. Further, diets meant for reducing LDL-C may reduce HDL-C to a similar degree (Hunninghake, D. B. et al, N. Engl. J. Med., 1993, 328:1213-19; Schaefer, E. J., et al, Arterioscl. Thromb. Vasc. Biol., 1995, 15:1079-85); Stefanick, M. L., N. Engl. J Med, 1998, 339:12-20).
Drug therapy is resorted to when the desired effects are not achieved with diets alone. Statins are the most popular among the lipid lowering drugs. These drugs lower serum LDL-C concentrations by upregulating LDL-receptor activity as well as reducing the entry of LDL into the circulation. The maximal reductions achieved with a statin ranges from 24-60%. Statins also reduce the serum TG levels; but they are often insufficient. Statins are ineffective in the treatment of patients with chylomicronemia. Adverse effects of statins include, gastrointestinal upset, muscle aches and hepatitis. Rarer problems include myopathy (muscle pain with serum creatine kinase concentrations more than 1,000 U per litre), rashes, peripheral neuropathy, insomnia, bad or vivid dreams and difficulty in sleeping or concentrating (Abramowica, M., Med Lett., 1996, 38:67-70; Vgontzas, A. N. et al, Clin. Pharmacol. Ther., 1991, 50:730-37; Roth, T. et al, Clin. Cardiol., 1992, 15:426-32; Partinen, M. et al, Am. J. Cardiol., 1994, 73:876-80). Other lipid-lowering drugs include bile acid-binding resins (e.g, cholesteramine and colestipol), nicotinic acid, and fibrates.
Drug therapy is not recommended for premenopausal women and men under 35 years of age unless they have serum LDL-C concentrations of more than 220 mg/dl (5.7 mmol/l), because their immediate risk of heart disease is low [Summary of the second report of the National Cholesterol Education Program (NCEP): expert panel on detection, evaluation and treatment of high blood cholesterol in adults, JAMA, 1993, 269:3015-23].
Thus, diets alone or in conjunction with lipid lowering drugs fail to yield the desired goal of safe lipid lowering. However, this goal is achievable with the present inventive composition containing the active principles of Emblica officinalis. Emblica has been in safe use in India for thousands of years as component of Ayurvedic preparations. The composition offers the twin benefits of reducing the harmful LDL cholesterol and enhancing the desirable HDL cholesterol.
Further, the composition was found to reduce the intima-media thickening of the arteries in experimental animals which is an added benefit. Such an effect has not been observed before.
Amla's cholesterol lowering effects have been reported in a few studies. Thakur et al studied the effect of amla on cholesterol-induced atherosclerosis in rabbits (Thakur, C. P. and Mandal, K., Indian J Med Res, 79: 142-6 1984; Thakur C P, et al. Int J Cardiol, 1988, 21:167-75). The control group was fed with cholesterol alone and the experimental group, amla and cholesterol for 16 weeks. Cholesterolemia was found to be significantly less in amla group (205 mg/dl) than in the control group (630 mg/dl). Aortic sudanophilia was significantly less in the amla group (12%) than in the control group (38%). The cholesterol contents of the liver and aorta, respectively, were significantly less in the amla group (46 mg/100 g, 42 mg/100 g), than in the control group (604 mg/100 g, 116 mg/100 g). Amla did not influence serum triglyceride (TG) levels, euglobulin clot lysis time or platelet adhesiveness. Another study (Mathur R, et al. J Ethnopharmacol, 1996, 50:61-68) found that serum cholesterol, TG, phospholipids and LDL cholesterol were lowered 82%, 66%, 77% and 90%, respectively, when fresh amla juice was fed to rabbits. Aortic plaques were regressed. Amla juice-treated rabbits excreted more cholesterol and phospholipids. Similar results have been reported by others (Mishra M, et al. Br J Exp Pathol, 1981, 62:526-28; Tariq M, et al. Indian J Exp Biol, 1977, 15:485-86).
Amla was found to inhibit cholesterol synthesis in rats (Anila I, Vijayalakshmi N R, J Ethnopharmacol, 2002, 79:81-87) by inhibiting the cholesterol synthesizing enzyme HMG CoA reductase. Degradation and elimination of cholesterol was noted, and thus the hypercholesterolemia induced by amla was suggested to be due to inhibition of synthesis and enhancement of degradation.
Oxidized LDL (ox-LDL) is one of the etiological factors of atherogenesis. A study was conducted to see if the antiatherogenic effects of amla was due to its effect on ox-LDL (Duan W, et al. Yakagaku, 2005, 125:587-91). Human umbilical vein endothelial cells (HUVEC) was incubated with ox-LDL and corilagin and its analogue Dgg 16 (present in amla) and then incubated with monocytes. Malondialdehyde (MDA) in the culture media was then determined. Monocytes adhering to the HUVEC were counted by cytometry. In another experiment, rat vascular smooth muscle cells (VSMC) were incubated in the media with or without ox-LDL and with corilagin and Dgg 16 at different doses and cell proliferation was assayed. Both corilagin and Dgg 16 were able to reduce MDA, prevented HUVEC from adhering to monocytes, and inhibited VSMC proliferation induced by ox-LDL. The authors concluded that the antiatherogenic effect of amla is due to corilagin and Dgg-16. Ethyl acetate extract of amla was a stronger antioxidant than probucol in preventing LDL oxidation (Kim H J, et al. J Nutr Sci Vitaminol, 2005, 51:1812-18).
So far no study has reported the HDL enhancing effect of amla, as described in the present invention.
Inflammation
An important component of atherosclerotic process is inflammation (Ross, R, N Engl J Med, 1999, 340:115-26; Libby P, Nature, 2002, 420:868-74). The fundamental appreciation that inflammation is an important and possibly even obligatory component of lesion initiation and progression, and also participates in the plaque rupture that mediates thrombotic complications and clinical events, has fundamentally changed the view of the pathogenesis of atherosclerosis. Thus correcting dyslipidemia alone does not reduce the risk of cardiovascular disease, or of clinical events in patients with established disease.
Considering the importance of inflammation in atherosclerosis, attention has been directed to search for mediators which are appropriate for monitoring inflammation. The most reliable marker for inflammation has been found to be the blood levels of C-reactive protein (CRP) (Pepys M B, Hirschfield, G M, J Clin Invest, 2003, 111:1805-12; Ridker P M, et al. N Engl J Med, 2005, 352:20-28). Clinical studies have shown the association of elevated plasma levels of CRP and increased cardiovascular risk (Shishehbor M H, et al. Cleve Clin J Med, 2003, 70:634-40). Especially chronically elevated CRP levels measured by high sensitive assays (hs-CRP) can independently predict the risk of cardiovascular events (Ridker P M, Circulation, 2003, 107:363-69). Patients with acute coronary syndrome after have elevated plasma levels of CRP (Nieminem M S, et al. Eur Heart J, 1993,14:(suppl K): 12-16). CRP has also been reported to determine the prognosis of developing arterial ischemia in healthy persons (Ridker P M, et al, N Engl J Med, 2000, 342:836-42; Harris T B, et al. Am J Med, 1999, 106:506-12; Ridker Pm et al, JAMA, 2001, 285:2481-85). In patients with cardiovascular disease who underwent coronary intervention, it can predict the risk of developing myocardial infarction and death (Chew D P et al, Circulation, 2001, 104:992-97; Lenderink T, et al. Eur Heart J, 2003, 24:77-86). CRP is a sensitive marker for inflammation leading to arteriosclerosis and monitors the inflammatory process in the arterial wall. It also has a direct influence on arterial injury. In the presence of CRP, endothelial adhesion molecules are significantly upregulated (Paceri V, et al. Circulation, 2000, 102:2165-68). CRP furthermore can stimulate monocytes to produce tissue factor, an important initiator of the clotting cascade (Cermal J, et al. Blood, 1993, 82:513-20). These data underlie the utility of CRP measurements in predisposed persons, and also suggest role for antiinflammatory therapy in those patients. It has been suggested that patients with coronary artery disease do benefit from reduction of CRP levels (Tomoda H, Akoi N, Am Heart J, 2000, 140:324-28; Ridker PM et al. Circulation, 1999, 100:230-35; Ridker P M, et al. N Engl J Med, 2005, 352:20-28).
CRP, thus, is not just a marker of inflammation, but an agent involved in the atherogenic process as well as a predictor of future cardiac events. Hence the need to keep the CRP to normal levels.
Amla's effect on CRP and on inflammation in general, has not been reported earlier. In one embodiment, the disclosed amla product has been found to be a robust agent to reduce CRP in human volunteers in the present invention.
Hyperglycemia
Diabetes mellitus magnifies the risk of cardiovascular morbidity and mortality (Resnick He, et al. J Clin Epidemiol, 2001, 54:869-76; Beckman J A, et al. JAMA, 2002, 287:2570-81). Besides the well-recognized microvascular complications of diabetes such as nephropathy and retinopathy, there is a growing epidemic of macrovascular complications including diseases of the coronary arteries, peripheral arteries and carotid vessels, particularly in the burgeoning type 2 diabetic population.
Coronary artery disease (CAD) causes much of the serious morbidity and mortality in diabetic patients who have a 2- to 4-fold increase in risk of CAD (Haffner S M, et al. N Engl J Med, 1998, 339:229-234). This has been observed a number of large trials (Kjaergaard Sc, et al, Scand J Cardiovasc J, 1999, 33:166-70; Malmberg K, et al, Circulation, 2002, 102:1014-19; Zuanetti G, et al. J Am Coll Cardiol, 1993, 22:1788-94; Shindler D M et al, J Am Coll Cardiol, 2000, 36:1097-1103). Patients with diabetes also have an adverse long-term prognosis after myocardial infarction (MI), including increased rates of reinfarction, congestive heart failure and death (Malmberg K, et al, Circulation, 2002, 102:1014-19). A Finnish study on trends of MI showed that diabetes increased 28-day mortality by 58% in men and 160% in women (Miettinen H, et al., Diabetes Care, 1998, 21:69-75). The 5-year mortality rate following MI may be as high as 50% for diabetic patients, more than double that of nondiabetic patients (Herlitz J, et al. Diabetes Med, 1998, 15:308-14). Such results led the Adult Treatment Panel III of the National Cholesterol Education Program to establish diabetes as a CAD risk equivalent mandating aggressive antiatherosclerotic therapy (JAMA, 2001, 285:2486-97).
Hyperglycemia (increased blood sugar levels), a cardinal manifestation of diabetes, adversely affects vascular functions, lipids, and coagulation. Intensive treatment of hyperglycemia reduces the risk of microvascular complications such as nephropathy and retinopathy, as shown by the United Kingdom Prospective Diabetes Study (UKPDS) (UKPDS 33, Lancet, 1998, 352:837-53). In a meta-analysis of more than 95,000 diabetic patients, increases in cardiovascular risk depended directly on plasma glucose concentrations and began with concentrations below the diabetic threshold (Coutinho M, et al. Diabetes Care, 1999, 22:233-40).
Diabetes also causes abnormalities in lipid profile, including elevated triglyceride levels, decreased HDL levels and increased levels of small, dense LDL. Elevated levels of triglyceride-rich lipoproteins lower HDL levels by promoting exchanges of cholesterol from HDL to VLDL (Sniderman A D, et al. Ann Intern Med, 2001, 135:447-59). Diabetic patients with CAD more commonly have elevated triglyceride and low HDL levels than elevated total cholesterol and LDL cholesterol levels (Rubins H B, et al. Am J Cardiol, 1995, 75:1196-1201). HDL normally protects LDL from oxidation, but this ability is impaired in diabetic patients (Gowri M S, et al. Arterioscl Thromb Vasc Biol, 1999, 19:2226-33).
Thus controlling hyperglycemia is important to prevent diabetic as well as cardiovascular complications.
Hypoglycemic effects of amla has not been described earlier. However, such effects of two polyherbal compositions (Triphala and Hyponidd) of which amla is a constituent have been reported (Sabu M C, Kuttan R, J Ethnopharmacol, 2002, 81:155-60; Babu P S et al. J Pharm Pharmacol, 2004, 56:1435-42). Triphala is a mixture of three herbal extracts, whereas ten herbs constitute Hyponidd. The latter also contain known hypoglycemic herbs such as Momordica charantia and Gymnema sylvestre. As described in the present invention, the amla product is found to possess hypoglycemic properties.
Thyroid Dysfunction
Thyroid hormone excess and deficiency are common (Hollowell J G, et al. J Clin Endocrinol Metab, 2002, 87:489-99; Vanderpump M P, et al. Clin Endocrinol (Oxford), 1995, 43:55-68) and are readily diagnosed and treated. A number of studies suggest that abnormal levels of thyroid stimulating hormone (TSH) may represent a novel risk factor for cardiovascular diseases (Hak A E, et al. Ann Intern Med, 2000, 132:270-78; Parle J V, et al. Lancet, 2001, 358:861-65; Imaizumi, M, et al. J Clin Endocrinol Metab, 2004, 89:3365-70; Kvetny J, et al. Clin Endocrinol (Oxford), 2004, 61:232-38; Walsh J P, et al. Arch Intern Med, 2005, 165:2467-72). Even mildly altered thyroid status reportedly affects serum cholesterol levels (Danese M D, et al. J Clin Endocrinol Metab, 2000, 85:2993-3001; Vierhapper H, et al Thyroid, 200, 10:981-84; Canaris G J, et al. Arch Intern Med, 2000, 150:526-34) heart rhythm (Sawin C T, et al. N Engl J Med, 1994, 331:1249-52) and rate (Bell G M, et al. Clin Endocrinol(Oxford), 1983, 18:511-16), ventricular function (Biondi B, et al. J Clin Endocrinol Metab, 2000, 85:4701-05; Idem, Ibid, 1999, 84:2064-67), risk of coronary artery disease (Hak A E, Loc cit; Walsh J P, loc cit; Cappola A R, et al. J Clin Endocrinol Metab, 2003, 88:2438-44).
Thyroidisms are classified into various categories (Cappola A R, et al. JAMA, 2006, 295:1033-41) as euthyroidism (normal TSH concentrations (0.45 to 4.5 mU/L), subclinical hyperthyroidism (TSH concentration 0.10 to 0.44 mU/L0, or less than 0.10 mU/L with a normal free thyroxine (FT4) concentration; subclinical hypothyroidism (TSH concentration more than 4.5 mU/L and less than 20 mU/L with a normal FT4 concentration, and overt hypothyroidism with a TSH concentration of 20 mU/L or more. In overt hyperthyroidism, the TSH levels are suppressed much below the normal levels, usually undetectable, or can be measured in a third-generation assay capable of detecting 0.01 mU/L (Shrier M D, Burman K D, Am. Fam Phys, 2002, 65:431-38).
Thyroid hormone has relevant effects on the cardiovascular system (Klein I, Ojama K, N Engl J Med, 2001, 344:501-09; Fazio, S et al. Recent Prog Horm Res, 2004, 59:31-50). Many symptoms and signs recognized in patients with overt hyper- and hypothyroidisms are due to the increased or reduced action of the thyroid hormone on the heart and vascular system, respectively Subclinical thyroid dysfunction may affect the cardiovascular system, which may increase the cardiovascular risk. In addition, patients with acute or cardiovascular disorders have abnormalities in peripheral thyroid hormone metabolism that may alter cardiac functions. The morbidity and mortality associated with hypothyroidism are apparently related to the atherogenic and prothrombotic vascular modifications that follow thyroid hormone deficiency, whereas heart failure and particularly atrial fibrillation and its thromboembolic complications are the primary consequences of hyperthyroidism. In both cases, return to normal thyroid levels corrects the cardiac abnormalities caused by thyroid dysfunction.
Amla has been found to be beneficial in hyperthyroidism, though the study was limited to mice (Panda S, Kar A, Pharmazie, 2003, 58:753-56). Amla fruit extract was evaluated for its effects on the L-thyroxine (L-T4)-induced hyperthyroidism in mice. While an increase in serum T3 (triiodothyronine) and T4 (thyroxine) concentrations, and in a thyroid dependent parameter, hepatic glucose 6-phospatase (glu-6-pase) activity was observed in L-T4 (0.5 mg/kg/d) treated animals, simultaneous oral administration of the plant extract at a dose of 250 mg/kg/d (p.o.) for 30 days in hyperthyroid mice reduced T3 and T4 concentrations by 64 and 70% respectively as compared to a standard antithyroid drug, propyl thiouracil that decreased the levels of the thyroid hormones by 59 and 40% respectively. The plant extract also maintained nearly normal value of glu-6-pase activity in hyperthyroid mice.
Results reported in the present invention is the first report on the effect of amla in thyroid dysfunction in humans.
Intima-media Thickening
The increased thickness of intima plus media of the carotid artery is associated with the prevalence of cardiovascular diseases and a number of studies have shown a positive association between cardiovascular risk factors and carotid intima-media thickness (IMT) (O'Leary, D. H. et al., Stroke, 1992, 22:1156-63; 1992, 23:1752-60; New Engl. J. Med, 1999, 340(1):14-22; Howard, N. et al, Ann. Int. Med., 1998, 128(4):262-69); Zureik, M. et al, Stroke, 1999, 30:550-55; del Sol, A. I. et al, Stroke, 2001, 32:1532-38). Howard et al (loc.cit.) makes the following statement: For each 0.03 mm increase per year in carotid arterial IMT, the relative risk for non-fatal myocardial infarction or coronary death was 2.2(95% CI, 1.4-3.6) and the relative risk for any coronary event was 3.1. Absolute IMT was also related to risk for clinical coronary events. Absolute thickness and progression in thickness predicted risk for coronary events beyond that predicted by coronary arterial measures of atherosclerosis and lipid measurements. A growing number of epidemiological studies and clinical trials use IMT as an early marker of systemic atherosclerosis (Zanchetti, A., et al, J. Hypertens., 1998, 16:949-61; MacMahon, S. et al, Circulation, 1998, 97:178-90: Borhani, N. O. et al, JAMA, 1996, 124:548-56; Hodis, H. N. et al, Ann. Intern. Med, 1996, 124:548-52).
IMT is increasingly being used in clinical trials as surrogate end point for determining the success of interventions that lower risk factors for atherosclerosis. To distinguish early atherosclerotic plaque formation from thickening of the intima-media, the following consensus has evolved (Touboul, P. J. et al, Mannheim Intima-Media Thickness Consensus, on Behalf of the Advisory Board of the 3rd Watching the Risk Symposium 2004,13th European Stroke Conference, Mannheim, Germany, May 14, 2004, Cerebrovasc. Dis., 2004, 18(4):346-49): Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness of ≧1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is recommended in all epidemiological and interventional trials dealing with vascular diseases to improve characterization of the population investigated.
Endothelial vasodilator dysfunction and carotid IMT are two indicators of subclinical cardiovascular disease. In a study of a large, community-based cohort of young adults (aged 24-39 years), Jounala et al (Circulation, 2004, 110(18):2918-23) found that IMT was inversely associated with endothelium-dependent brachial artery flow-mediated dilation (FMD). The number of risk factors was correlated with increased IMT in subjects with evidence of endothelial dysfunction. In a related study, FMD and glyceryl trinitrate-induced endothelium-independent vasodilation (GTN) were measured in the brachial artery. IMT of the common carotid artery and insulin sensitivity were also measured. There was a significant positive relation between insulin resistance, as measured by steady-state glucose levels, and IMT. Insulin resistance was negatively correlated with both FMD and GTN. This indicates that both FMD and GTN were also negatively correlated with IMT (Suzuki, M. et al., Am. J. Hypertens, 2004, 17(3):228-32). Similarly, in a study on 252 healthy adults, IMT was significantly greater in subjects with subclinical aortic valve sclerosis (Yamamura, Y., et al, Am. J. Cardiol., 2004, 94(6):837-39). To determine whether IMT is related to an increased risk of cardiovascular event after percutaneous coronary angioplasty (PTCA), IMT was measured within 2 days following PTCA in 88 patients (mean age 62 years) in another study. A common carotid IMT>0.7 mm was associated with an increased risk of cardiac events after PTCA (Lacroix, P. et al., Int. Angiol., 2003, 22(3):279-83).
Low HDL cholesterol was associated with increased IMT independent of other risk factors in healthy subjects from families with low HDL cholesterol (Alagona, C., et al, Eur. J. Clin. Invest., 2003, 33(6):457-63). Conversely, increased HDL cholesterol was negatively correlated with IMT (Blankenhom, D. H., et al, Circulation, 1993, 88(1)20-28; Bonithon-Kopp, C. et al, Arterioscl. Thromb. Vasc. Biol, 1996, 16:310-16).
A statistically significant IMT greater than 0.8 mm was associated with coronary artery disease with an odds ratio of 2.4 in Indian subjects (Jadhav, U. M. and Kadam, N. N., Indian Heart. J., 2001, 53(4):458-62). The same authors also found (J. Assoc. Physicians India, 2002, 50:1124-29) a statistically significant association of microalbuminuria with IMT and coronary artery disease in diabetic patients.
In a large population-based of 6943 subjects, carotid IMT and aortic calcification were found to be the strongest predictors of stroke (Hollander, M. et al., Stroke, 2003, (10):2368-72).
From the foregoing, the importance of IMT in cardiovascular disease management is amply evident. Fortunately, IMT is modifiable. Various synthetic drugs, for example, colestipol plus niacin (Blankenhom, D. H., Circulation, 1993, 88(1):20-28), candesartan (Igarashi, M. et al, Hypertension, 2001, 38(6):1255-59), simvastatin (Detmers, P. A., et al, Circulation, 2002, 106(1):20-23), rampamycin with tacrolimus or cyclosporin (Weller, J. R., et al, Br. J. Surg., 2002, 89(11):1390-95), calcium channel blockers (Wang, J. G. and Staessen, J. A., J. Am. Soc. Nephrol., 2002, 13 Suppl:S208-15), sulfated oligosaccharide PI-88 (Francis, D. J., et al, Circ. Res., 2003, 92(18):70-77), fluvastatin (Ye, P. et al, Chin. Med. Sci. J., 2000, 15(3):140-44), lovastatin (Furberg, C. D., et al, Circulation, 1994, 90:1679-87), chemically modified tetracycline (Islam, M. M., et al, Am. J. Pathol., 2003, 163(4):1557-66) reduce IMT. There are very few natural products which are reported to suppress intimal thickening. Thus, the finding that Emblica extract can reduce IMT assumes great significance.
The disclosed amla product was found to reduce IMT in rabbits. Though the reduction in IMT has not been proven in humans, it is expected such results may be achieved in human beings as well because IMT is inversely associated with HDL concentration (Watanabe et al. Arterioscl Thromb vasc Biol, 2006, 26:897-902; Alagona C et al. Atherosclerosis, 2002, 165:309-16; Eur J Clin Nutr, 2003, 33:457-63). IMT is also positively correlated with CRP (Wang T S et al. Arterioscl Thromb Vasc Biol, 2002, 22:1662-67; Sitzer M, et al. J Cardiovasc Risk, 2002, 9:97-103). Diabetes is also associated with increased IMT (Mohan V, et al. Diabetes Med, 2006, 23:845-50; Wagenknecht L E et al. Diabetes Care, 1998, 21: 1812-18; Brohall G, et al. Diabet Med, 2006, 23:609-16). Thus, it is reasonable to expect that the disclosed amla product would reduce IMT, indirectly indicating regression of atherosclerosis.
The present inventive composition, by its direct effects on dyslipidemia, inflammation, hyperglycemia and intima-media thickening, thus offers much improved cardioprotection than any other similar product, natural or synthetic, with the added benefit of its time-tested safety.
Ghosal has disclosed a process for preparation of an extract of Emblica officinalis (U.S. Pat. No. 6,124,268) and a few more by the same inventor for various applications of the preparation, such as, stabilization of vitamin C (U.S. Pat. No. 6,235,721), inhibiting platelet aggregation (U.S. Pat. No. 6,290,996) and antioxidant to block free radical process (U.S. Pat. No. 6,362,167). In none of the above patents, the hypocholesterolemic action, and more specifically, its HDL enhancing property or other properties described in the present invention, have been described. The present inventive preparation also materially differs in composition from that described by Ghosal. The extraction process described by Ghosal involves treating the fruit pulp with water containing 1% sodium chloride which was then left at room temperature for 12 hours followed by keeping the mixture at 10° C. for 3 days and thus is very time-consuming, costly and tedious. Further, he uses sodium chloride solution for extraction and apparently, the salt remains in the final preparation. This may not be desirable, given the adverse affects of salts for patients with hypertension which is closely associated with cardiac diseases. Further, going by the examples given in the said Ghosal patent, the content of active principles, which he calls as the antioxidant fraction, is less than 4% in the final preparation. Thus, a more commercially attractive process would be highly desirable.